Method of stimulating parthenocarpy in plants

ABSTRACT

Plant growth regulating compositions which comprise quinone derivatives having isoxazole ring as active ingredients.

United States Patent [191 p Kano et a1. Sept. 23, 1975 [54] METHOD OF STIMULATING 3,381.016 4/1968 Marklillie 71/88 PARTHENOCARPY 1N PLANTS 3.547940 12/1970 Brantley 71/88 3,578,673 /1971 Bruson et al 71/88 Inventors: Hideo Kano, lbaraki; Masaru Ogata,

Kobe; Hisajiro Yukinaga, Kusatsu, all of Japan Assignee: Shionogi & Company Japan Filed: Jan. 23, 1974 Appl. No.: 435,968

Related US. Application Data Division of Ser. No. 237,970, March 24, 1972, abandoned.

Foreign Application Priority Data Mar. 31, 1971 Japan 46-19411 Mar. 31, 1971 Japan 46-19412 US. Cl. 71/88; 71/67; 71/94;

260/296 H; 260/296 T; 260/307 D Int. Cl. AOIN 9/00 Field of Search 71/88 References Cited UNITED STATES PATENTS 1/1957 DAmico 71/88 OTHER PUBLICATIONS Bianchi et a1., "Convenient Synthesis of lndoxazenes (1966) CA pp. 7160-7161, (1966).

Quihco et a1., Ricerche Sugli Osidi Di Nitrile" (1950) Gazz. Chim. ltal. pp. -150 (1950).

Morrocchi et a1. 1, Reazine Dei P-Chinoni Con etc.," (1968), Gazz. chim. ital. 98, pp. 891-906 (1968).

Morrocchi et a1. 11, Studio Delle Strutture Chivoniche etc., (1969) Gazz. Chim. Ital. 99 pp. 565-581 (1969).

Primary ExaminerGlennon H. l-lollrah Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [57] ABSTRACT Plant growth regulating compositions which comprise quinone derivatives having isoxazole ring as active ingradients.

12 Claims, No Drawings METHOD OF STIMULATING PARTHENOCARlY lN PLANTS wherein R is a halogen atom (cg. chlorine, bromine, iodine, fluorine), a lower alkyl group (e.g. methyl, ethyl, propyl, isopropyl, butyl, pentyl), a phenyl group or a pyridyl group; A is a condensed benzene ring or a condensed pyridine ring; X and Y each is an oxygen atom or the group of and where A and R may have one or more substituents selected from the group consisting of hydroxy group,

lower alkyl groups (c.g. methyl, ethyl, propyl. isopropyl. butyl, pentyl), lower alkoxy groups (c.g. methoxy, ethoxy, propoxy, butoxy), primary, secondary or tertiary lower alkyl amino groups (c.g. amino. methylamino, ethylamino, propylamino, dimethylamino, diethylamino) and halogen atoms (e.g. chloride, bromide, iodine, fluorine).

It has been discovered that the said quinone derivatives of the formula [I] or [ll] have plant growth regulating activity. t

Accordingly, a basic object of this invention is to provide novel plant growth regulating compositions containing an effective amount of one or more quinone derivatives of the formula [I] or [ll] in combination with suitable agricultural carriers and other ingredients. A further object of the invention is to provide novel quinone derivatives having plant growth regulating activity. A still further object of the invention is to provide a method to modify or regulate the growth pattern of plants by application of the said compositions. These and other'objects and the manner in which they are accomplished will become apparent to those conversant with the art from the following descriptions.

The quinone derivatives [l] or [ll] contained in the composition of the invention can be prepared by condensing 1,4- or 1,2-quinone compounds [Ill] or [W] with a suitable nitrile oxide according to the methods substantially described in Gazz. Chim. Ital. 80. 140 (I950), Gazz, Chim. ltal. 98, 891 (1968) and Gazz. Chim. ltal. 99, 565 (1969), as illustrated in the following equations.

A. Preparation of quinone derivatives [I] B. Preparation of quinone derivatives [ll] {RCNOIn a a t],

wherein R, A, X and Y each has thesame significance quinone compounds ['III] or [IV] may be made to react with one to three moles of the nitrile oxide [V] acco r ding to the object, i.e'. which product is intended to be produced. Generally, the reaction is executed at a temperature ranging from about 10 to about 80C for about l to about 3 hours under ordinary (atmospheric) pressure, while the reaction conditions may be varied depending on the properties of starting compounds [H1] or [IV] and the nitrile oxide [V]. The reaction solvent may be selected from, for example, alcohols (e.g. methanol, ethanol), halogenoalkanes (efg. chloroform, te'trachloromethane), ethers (e.g. ether, dioxane, tetrahydrofuran), aromatic hydrocarbons e.g. benzene, toluen'e, xylene), and the like in consideration of the solubility of the starting compounds as well as other reac' tion conditions employed. I

The nitrile oxide [V] can be prepared from the corresponding aldehyde oxime. The aldehyde'oxime is first halogenated to give hydroxamyl halogenide and the hydroxamyl halogenide. is subjected to dehydrohalogenation with a basic substance to give the desired nitrile oxide. The reaction for preparing the nitrile oxide may be illustrated as follow: I

wherein X represents a halogen atom and R has the same significance as designated above.

The basic substance may be selected from, for example, alkali metal hydroxides, alkali metal carbonates, alkali metal alkoxides, alkali metal salts of organic or inorganic acid, ammonia, primary, secondary-and tertiary amines and the like. Thus prepared nitrile oxide [V] is very unstable. Therefore, it-is preferred to use the nitrile oxide [V] prepared just before the condensation reaction and without isolation'from'the reaction mixture in which'the nitrile oxideis prepared. Further, ifit is intended to produce a product [I] or [II] in which X and Y each is an oxygen atom, it may be recommended to carry out the reaction in the presence of an oxidizing agent (e.g. hydrogen peroxide, chloranile,

3-phenyl-4.9-dihydronaphthol 2.3-d ]isoxa7.ole-4.9-,

dione. I

3-phenyl-6.7-dimethoxy-4,9-dihydronaphtho[ 2,3-

d isoxazole-4,9-dione.

3-(4-ehlorophenyl )-6,7-dimcthyl-4,9-

dihydro'naphtho[2.3-d]isoxazole-4,9-dione.

3-( 4-chlorophenyl )-4.9-dihydronaphtho[ 2,3,-

d]isoxazole-4.9-dione,

3-( 2.4-dichlorophenyl )-6,7-dimethyl-4,9-

dihydronaphtho[ 2,3-d ]isoxazole-4.9-dione,

3-( 4-methoxyphenyl )'4,9-dihydronaphtho[ 2,3-

d isoxazole-4,9-dione,

3-( 3-pyridyl )-4 9-dihydronaphtho[ 2,3-d1isoxazole- 4,9-dione,

3-(4-methylphenyl )-6,7-dimethyl-4.9-

dihydronaphtho[ 2,3-d ]isoxazole-4,9-dione,

, 3-phenyl-4,9-di hydroisoxazolol4,5-g]quinoline-4,9-

dione, 3-(3-pyridyl) 4,9-dihydroisoxazolo[ 5,4-g1quinoline- 4,9-dione, 3-methyl-4,9-dihydroisoxazolol 5 ,4-g]quinoline-4,9-

dione, 3-phenyl-4,9-dihydroisoxazolo[4,5-g]isoquinoline- 4,9-dione,

3,5-diiodo-4-oxo-4,9-dihydronaphtho[2,3-

- 3,5-diphenyl-4-oxo-4,9-dihydronaphtho[2,3-

1 3,5-di-(3,5-dibromophenyl)-4-oxo-4,9-

' 3,5'-di(3-methylphenyl)-4-oxo-6,7-difluor0-4,9-

7 3,5 -di-( 3-pyridyl )-4-oxo-4,9-dihydronaphtho[ 2,3-

, 31,5 -diphenyl-4-oxo-4,9-dihydroisoxazolo[4,5-

' 3,5'-dibromo-4-oxo-4.9-dihydroisoxazolo[4,5-

- 3 ,5 -dimethyl-4-oxo-4,9-dihydroisoxazolo[ 5 ,4-

g]isoquin0line-9-spiro-2'-l ',3 ',4'-di-oxaole, 3-chl0ro-4.S-dihydronaphthol 2, l -d]isoxazole-4,5

dione,

4 3-methyl-4,5 -dihydronaphtho[ 2,] -d ]isoxazole-4,5-

' dione',

3 8-hydroxy-4,5-dihydronaphtho[ 2, 1 -d isoxazole- 4,5-dione,

-. 3-phenyl-7fchloro-4,5dihydronaphtho[2,l-

3-(4-methylphenyl);4,5 dihydronaphtho[2,l-

I 4,5-dione,

3-methyl-4.5-dihyd roisoxazolol 5 ,4-f] quinoline- -dione,

3-phenyl-4.5-dihydroisoxazolol 5 ,4f]quinoline-4,5-

dione.

3-( 3-pyridyl )-8-methyl-4.5-dihydroisoxazolo[4.5-

h]quinoline-4.5-dione,

3-phenyl-4,5-dihydroisoxazolo[ 4,5-h]isoquinoline- 4,5-dione,

3 .5 '-diiodo-4-oxo-4,5-dihydronaphtho[ 2. l d]isoxazole-5-spiro-2'1',3 ',4'-dioxazole.

3 .5 ,7 ,8,-tetramethyl-4-oxo-4,5-dihydronaphtho[ 2. l

d]isoxazole-5-spiro-2-l ,3 ',4'dioxazole,

3.5'-diethyl4-oxo-6-bromo-4,5-

dihydronaphtho[2,1-d]isoxazole-5-spiro-2- l.3 ,4'-dioxazole,

3 ,5 -dibutyl-4-oxo-4,5-dihydronaphtho[ 2. l

3 ,5 '-diphenyl-4-oxo-4.5-dihydronaphthol 2, l d]isoxazole-5-sprio-2'-l ',3,4-dioxazole.

3 .5 -di-( 3,5-dichlorophenyl )-4-oxo-9-methyl 4,5dihydronaphtho[2, l -d]isoxazole-5-spiro-2- l,3 ,4-dioxazole,

3,5 di-(4-methoxyphenyl )-4-oxo-4,5- I

The quinone derivatives of the formula [I] or [II] are useful for control of plant growth. For example. the quinone derivatives [l] and [II] show herbicidal and algicidal activities against a variety of weeds and algae including. for example, Monoclwria vagina/is. Rotula indic'a. Vandal/fa unugstifblia, (.yperus dlffin-mis. Spr'r0 gyra art-la and ()edogonium sp.. when applied at alevel of about 10 grams per are to about 80 grams per are, but are inactive to gramineous plants even at the same or slightly higher level. Therefore, they can be used at this level as a selective herbicide or algicide. Although the quinone derivatives [[1 and [II] have these and other growth regulating activities as a plant hormone, the most important and characteristic feature they show is parthenocarpy-stimulating activity.

As is well known, parthenocarpy-stimulating agents are important in cultivation of fruits in the green house. It has been discovered that the quinone derivatives [I] and [ll] have excellent parthenocarpy-stimulating activity against various fruits such as tomato. eggplant, cucumber, melon, water melon and the like. To illustrate the parthenocarpy-stimulating effect, the test resalts with tomato are shown in the following table.

Parthenocarpystimulating Effects of Some Typical Quinone Derivatives ll] and Ill] Test Variety Number of Number of Percentage of of Concentration Flowers Fruit Parthenocarpy Test Compound Tomato Lg/ml) Treated Developed Stimulated 3-Phcnyl-4.9-dihydronaphtho- [2,3-d ]isoxa7.ole-4.9-dione Miniature 50 32 10 3 I .3 100 34 12 35.3 250 34 6 17.6 Fukuju No. 2 250 9 8 88.9 3-( 3-ChIoro-4-dimethylaminophenyl)-4.9-dihydronaphtho 250 l0 1 10.0 I 2.3-d lisox:tzole-4.9-dione 3.5'-Diphenyl-4'oxo 4.9- dihydronaphthoI2.3-dl- Miniature" 50 29 3 10.3 isoxazole-Q-spiro-2'- l'.3.4' dioxazole I00 4 l3.3 250 29 4 I18 Fukuju No. 2" 19 4 2L2 100 20 5 25.0 350 22 13 59.0 3.5'-l)iphenyl-4-oxo-4.5- dihydronaphthol 2. l -d I "Miniature" 50 20 l 5.1) isoxaZole-5-spiro-2'- l'.3'.4'-dioxazole I00 20 2 10.0 250 20 3 l5.() None [control] 30 0 0 None (control) "Fukuju No. 2" 30 0 (l Test Methods I) With Miniature" tomato: When two or three of the first flower clusters began to flower, their stamens were removed, and the clusters were covered by paper bags to prevent pollination from non-emasculated flowers. The test solution was prepared by dissolving the test compound at a pro-determined concentration in water together with ug/ml of Tween 20. On the day after the removal of stamens. the test solution was sprayed onto the flower clusters. The number of developed fruit was counted after the fruit had colored, and parthenocarpy was confirmed by the fact that the fruit had no seeds.

(2) With Fukuju No.2" tomato: When two or three of the first flower clusters began to flower. their stamens and stigmas were removed. Then the flowers were soaked in test solution prepared in the same manner as described above. The number of developed fruit was counted after the fruit had colored, and parthenocarpy was confirmed by the fact that the fruit had no seeds.

It is apparent from the table that the test compounds have marked parthenocarpy-stimulating activity. In addition, it has been confirmed that they show no phytotoxicity against the test plant and that the fruit harvested is not inferior to those obtained by natural pollination either in size or in weight.

Since the other quinone derivatives of the present invention not listed in the table also show similar biological activity, all the quinone derivatives [I] and [Il] are extremely useful as parthenocarpy-stimulating agents.

The plant growth regulating compositions of the present invent-ion may be prepared in various conventional forms such as aerosols, solutions, emulsions,

emulsifiable concentrates, wettable powders, pastes, dusts, granules, pellets, tablets or the like according to the use intended. The composition may normally contain from about 0100001 percent by weight to about 90 percent by. weight of the quinone derivative [I] or [II] as an active ingredient, the amount contained depending on the formof composition as well as the use intended. To formulate'the'composition, suitable gaseous, liquid, or solid carriers and other ingredients including surface active agents are used in addition to one or more compounds of the quinone derivatives [1] or [II], and conventional techniques for mixing, blend.

ing, crushing, granulating, or tabletting may optionally be adopted.

The surface active agents used in preparing the compositions of the present invention can be wetting, dispersing, or emulsifying agents. They may act, for example, as wetting agents for wettable powders and dusts, as despersing agents for wettable powders and suspensions', and as emulsifying agents for emulsions and emulsifiable concentrates. Surfactants may also enhance the biological activity of the active ingredients.

Suitable surface active agents for use in the composior suitable inert organic solvents such as aliphatic hy- 'drocarbons (e.g. pentane, hexane, cyclohexane, petrotion include polyethylene glycol esters with fatty acids;

polyethylene glycol ethers with alkylphenols or with long-chain aliphatic alcohols; polyethylene glycol ethers with sorbitan fatty acid esters; and polyoxyethylenethio ethers. Other suitable surfactants include ammonium, alkali, or alkaline earth salts of alkylaryl sulfonic acids; ammonium, alkali, or alkaline earth fatty alcohol sulfates; fatty acid esters of ammonium, alkali or alkaline earth isothionates ortaurates; ammonium, alkali or alkaline earth salts of lignin sulfonic acids;

. methylated or hydroxyethylated cellulose; polyvinyl alleum ether, gasoline, kerosene), aromatic hydrocarbons (e.g. benzene, toluene, xylene), halogenated hydrocarbons(e.g methylene chloride, chloroform, carbon tetrachloride, trichloroethane), ketones (e.g. acetone, methyl ethyl ketone), ethers (e.g. ether, isopropyl ether, tetrahydrofuran, dioxane), esters (e.g. ethyl acetate, amyl acetate) or alcohols (e.g. methanol, ethanol, butanol). Solid carriers may be, for example, mineral powders (e.g. clay, talc, kaoline, bentonite, diatomaceous carth,.silica gel), vegetable powders (e.g. soybean powder, wheat powder), or other powders conventionally used as agricultural solid carriers or diluents.

More particularly, preferred forms of the composition of the present invention for use as a parthenocarpy-stimulating agent may be solutions, emulsions, emulsifiable concentrates or wettable powders. They may be diluted before application to a concentration of from about 1 ug/ml to about 1,000 ug/ml and sprayed on the objective plants at a stage of flowering. To ensure such effect, it may be recommended to repeat the treatment 2 or 3 times in the same day or over 2 or 3 days, though the full effect can usually be obtained by To a solution of 1,4-naphthoquinone 16.6 g) and triethylamine (12.8 g) in benzene (330 ml) is dropwise added another solution of p-methoxybenzhydroxamyl chloride (23.5 g") in ether (l ml) at l82lC. The reaction mixture is stirredfor 20 minutes and refluxed for 1 hour in'water bath. After the reaction, to the mixture is added water and extraction with benzene is cffected. The extract is dried over sodium sulfate and evaporated. The residue ischromatographed on alu- 1 mina. The benzene eluate is evaporated, and the resi- EXAMPLES 2 4 7 The products listed below can be prepared by substantially the same procedure as Example 1 from the corresponding starting compounds.

Ex. Source of No. Starting Compound Nitrile Oxide Product Properties of Product l,4-Naphthoquinone p-Chlorobcnzhydrox- 3-(4-Chlorophenyl)- m.p. l78-l78.5C. Yellow needles. amyl chloride 4.9-dihydronaphtho- Anal. Calcd. for C, H,,O;,NC|: 2 l2,3-d]is0xa7.ole- C. 65.92; H, 2.28; N, 4.52.

4,9-dione Found: C, 66.03; H. 2.6l; N. 4.36. 1.4-Naphthoquinonc 3-Pyridylearho- 3-(3-Pyridyl)-4.9- m.p. l87l90C. Yellow needles.

hydroxamyl chloride dihydronnphtho- Anal. Calcd. for c,..H,.o;,N 3 hydrochloride |2.3-,d]isoxazole- C. 69.56; H, 2.92; N, l().l4.' 4.9-dionc lound:,( 69.74; H, 2.72; N. 10.43. 6,7-Dimethyl-L4- 3-(4-Methylphenyl) m.p. 2l32l4C. Yellow 7 4 p-Mcthylhenzhydroxneedles.

To a solution of 1,4-naphthoquinone (4.4 g), triethylamine (3.36 g) and chloranile (3.45 g) in benzene (176 ml) is added p-methylbenzhydroxyamyl chloride (which is prepared from p-methylbenzaldehyde oxime (5.0 g), chlorine (3.58 g) and ether (150 ml).) and the mixture is refluxed for 2 hours. After addition of water,

the reaction mixture is extracted with benzene. The

benzene extract is washed with water. dried and evaporated. The residue is washed with benzene, and insoluble substance is filtered off. The filtrate is chromatographed on alumina and eluted with benzene and with methylene chloride. The eluates are combined, evaporated, and the residue is recrystallized from ethyl acetate-isopropyl ether to give 3-(4-methylphenyl)-4,9- dihydronaphtho[2.3-d]isoxazole-4,9-dione (1.902 g) as pale yellow needles. m.p. 138-146C.

Anal. Calcd.'for c n o w; C, 74.73; H, 3.83; N, 4.84. Found: C, 74.54; H. 3.77; N. 4.83.

EXAMPLE 9 To a solution of 6,7-dimethoxy-l.4-naphthoquinone (880 mg), triethylamine (490 mg) and chloranile (500 mg) in benzene (70 ml) is added another solution of benzhydroxamyl chloride (50 mg) in ether mlland the mixture is refluxed for 1 hour. The reaction mixture is treated by the same procedure as Example 8 to give 3-phenyl-6,7-dimethoxy-4.9dihydronaphthol2,3- d]isoxaz'ole4.9-dione (413 mg). Recrystallization from benzene gives orange crystals melting at 242244C.

Anal. Calcd. for o l-1, 051% C. 68.06; H, 3.91; N,

4.18. Found: c. 68.28; H. 4.10; N. 4.10.

EXAMPLE Continued Ex. Source of No. Starting Compound Nitrile Oxide Product Properties of Product naphthoquinone amyl chloride 6.7-dimethyl-4.9- Anal. Calcd. for C...,H,.,0 N;

4 dihydronuphtho- C. 75.69: H. 4.76: N. 4.41.

[2.3-dlisoxazole- Found: C. 75.65; H. 4.73; N. 4.48. 4.9-dione 6.7-Dimethyll .4 p-Chlorohenzhydrox- 3-(4-Chlorophenyl)- m.p. 213220C. Yellow needles.

. naphthoquinone amyl chloride 6.7-dimcthyl-4.9-di- Anal. Calcd. for C H O NCI:

5 hydronaphthol2 3-d|- C. 67.57; H. 3.58: N. 4.15.

isoxazoleAH-dione Found: C. 67.69; H. 3.59; N. 4.22.

6.7 Dimethyl-l.4- 2.4-Dichlorohcnz- 3-(2.4-Dichloro m.p. 192-194C. Yellow needles. naphthoquinone hydroxamyl chloride phenyl)-6.7-di- Anal. Calcd. for C H o NCl 6 methyl4.9-dihydro- C. 61.31; H. 2.98; N. 3.76.

naphthol2.3-dlisoxa- Found: C. 61.17: H. 2.98; N. 3.76.

' zolc-4.9 dione 1.4-Naphthoquinone 3Chloro-4-dimethyl 3-(3chloro-4-dim.p. 168172C. Dark violet needles aminohenzhydroxamyl methylaminophenyl)- Anal. Calcd. for C H O N Cl:

7 chloride 4.9-dihydronaphtho- C. 64.69; H. 3.71; N. 7.94. [2.3-dlisoxazolc- Found: C. 64.92; H. 3.73; N. 8.13 4.9-dione EXAMPLE 8 quinone condensed with two moles of pyridinenitrile oxide (95 mg) as colorless plates (m.p. 218222C). The crystals are supposed to be one of the following four isomers:

1. 3.5 '-di-( 3-pyridyl)-4-oxo-4,9-

dihydroisoxazolo[4,5-g]quinoline-9-spiro-2'- 1',3',4'-dioxazole 2. 3.5'-di-(3-pyridyl)-4-oxo-4,9-

dihydroisoxazolo[5,4-g]quinoline-9-spiro-2" 1,3,4-dioxazole residue is washed with isopropyl ether to precipitate 3- (3-pyridy1)-4,9-dihydroisoxazolo[4,5 or 5.4- g]quinoline-4.9-dione (360 mg). Recrystallization from ethyl acetate gives pale yellowish green needles melting at 206209C.

Anal. Calcd. for C H O N .C, 64.98; H. 2.54; N, 15.16. Found: C, 65.13; H, 2.68; N. 15.22.

EXAMPLE 1 1 To a solution of quinoline-5,8-quinone (795 mg). triethylamine (606 mg) in benzene (80 ml) is gradually added benzhydroxamyl chloride (856 mg) at about 15C with stirring and the mixture is refluxed for 1 hour. To the reaction mixture is added water and ether and the resinoid substance is removed by filtration. The

filtrate is extracted with ether. The extracts are com-' bined. washed with water, dried over sodium sulfate and evaporated. The residue is washed with methylene chloride to give 3-phenyl-4.9-dihydroisoxazolo[4.5 or 5,4-g]-quinoline-4,9-dione as yellow crystals. Recrystallization from ethyl acetate gives the product melting at 193-196C.

Anal. Calcd. for CwH OgNzI C, 69.56; H, 2.92; N, 10.14. Found: C, 69.33; H. 2.74; H, 10.15.

The methylene chloride washing and the ethyl acetate mother liquid of recrystallization are combined, chromatographed on alumina and eluted with benzene. The benzene eluate is evaporated to give residue. Recrystallization from ethyl acetate gives two kinds of ad- EXAMPLE 12 An emulsifiable concentrate of the following composition is prepared:

3-Phenyl-4.9-dihydronaphtho[ 2.3-d lisoxazole- 4.9-dione 1071 by weight Polyethylene alkylaryl ether 4% by weight Acetone 867: by weight The emulsifiable concentrate is diluted 200- to 1,000-fold with water before application for parthenocarpy stimulation.

EXAMPLE 13 An emulsifiable concentrate of the same composition as Example 12 is prepared except that 3-methyl-4,5- dihydronaphtho[2.l-d]isoxazole-4,5 -dione is used in lieu of 3-phenyl-4,9-dihydronaphtho[2,3-d]is0xazole- 4,9-dione.

The emulsifiable concentrate is diluted to 100- to SOO-fold with water before application for parthenocarpy stimulation.

EXAMPLE l4 An emulsifiable concentrate of the following composition is prepared:

3.5'-Diphcnyl-4-oxo-4.9-dihydronaphthol 2.3-d isoxazole-Q-spiro-2'-1-.3 .4'-dioxazole Polyoxyethylene alkylaryl ether Methylnaphthalenc lo /L by weight l()'7( by weight 8071 by weight The emulsifiable concentrate is diluted 200- to l(),()-fold with water before application for parthenocarpy stimulation.

EXAMPLE l5 An emulsifiable concentrate of the same composition as Example l4 is prepared except that 3.5'-diphenyl-4- oxo-4.5-dih ydronaphtho[ 2, l -d isoxazole-S-spiro-Z l,3,4-dioxazole is used in lieu of 3,5-diphenyl-4- oxo-4,'9-dihydronaphtho[2.3-d]isoxazo|e-9-spiro-2'- l.3,4'-dioxazole. I

The emulsifiable concentrate is diluted 100- to 500- fold with water before application for parthenocarpy stimulation.

EXAMPLE l6 An emulsifiable concentrate of the following compo sition is prepared:

3-(3 Pyridyl)-4.9dihydronaphtho[2.3d] isoxazole-4.9-dione It) '7! by weight Alkylphenyl ethyleneoxide I Q by weight Acetone 'r by weight Benzene 3) .4 by weight The emulsifiable concentrate is diluted 200- to 10.000-fold with water before application.

EXAMPLE 17 An emulsifiable concentrate of the following composition is prepared:

3.5'-Diphenyl4-oxo-9-iodo-4.5dihydroisoxazolo I 5.4-f]isoquinoline-5-spiro2'-l '.3'.4'-dioxazole Alkylphenyl cthyleneoxide Acetone Benzene HW! by weight 5 1 by weight 50% by weight 35% by weight The emulsifiable concentrate is diluted 100- to 500- fold with water before application.

EXAMPLE 18 A dust of the following composition is prepared:

' 3-(4Methoxyphenyl)-4.9-'

dihydronaphthol 2.3-d isoxazole4.9-dionc I l part by weight A mixture of talc and kaoline 20 parts by weight The mixture is blended and ground to obtain a dust.

EXA'MPLE 19 A dust of the same composition as Example 18 is prepared except 3.5-di-(3-pyridyl)-4-oxo-9-bromo-4,5- dihydroisoxazolo[5,4-f]isoquinoline-5-spiro-2'- l',3',4'-dioxazole is used in lieu of 3-(4 methoxyphenyl)4.9-dihydronaphtho[2,3-dlisoxazole- 4,9-dione.

EXAMPLE 20 A mixture of the following composition is prepared:

3-( 4 Ch|orophenyl )-4.9-dihydronaphthol 2.3 d]' isoxazole-4,9-dione Bentonite powder 20% by weight 8071 by weighl After blending. the mixture is kneaded with water, granulated, and drie'd'to' obtain granules.

EXAMPLE 21 A mixture of the same composition as Example 20 is prepared except 3-phenyl-4 5-dihydronaphtho[2,ld]isoxazole-4,5-dione is used in lieu of 3-(4- I chlorophenyl)-4,9-dihydronaphtho[2,3-d]isoxazole- 4,9-dione.

After blending, the mixture is kneaded with water. granulated. and dried to obtain granules.

What is claimed is: l. A method for stimulating parthenocarpy in fruit P bearingplants which comprises applying to said plants at the stage of flowering a parthenocarpy stimulating amount ofa composition comprising as an active ingreclient a compound selected from the group consisting of:

and

wherein R is a member selected from the group consisting of a 2. A method according to claim 1. wherein the halogen or halogeno moiety is selected from the group consisting of chlorine. bromine. iodine and fluorine.

3. A method according to claim 1. wherein the active ingredient is 3-phenyl-4.9-dihydronaphtho[ 2.3- d lisoxazole-49dione.

4. A method according to claim 1, wherein the active ingredient is 3-( 3-chloro-4-dimethylarninophenyl )-4.9-,

dihydronaphthol2.3-d]isoxazole-4.9-dione.

5. A method according to claim I. wherein the active ingredient is 3-phenyl-4.5-dihydronaphtho[2.] d]isoxazole-4.5-dione.

6. A method according to claim 1. wherein the active ingredient is 3-(4-methoxyphenyl)-4,9- dihydronaphth0[2.3-d]isoxazole-4.9-dione.

7. A method according to claim 1, wherein the active ingredient is 3-(4-chlorophenyl)-4.9- dihydronaphtho[2.3-d]isoxaz0le-4.9-dione.

8. A method according to claim 1, wherein the active ingredient is 3-methyl-4.5 -dihydronaphtho[2. l d]isoxazole4,5-dione.

9. A method according to claim 1 wherein the composition is in the form of a solution.

10. A method according to claim 1 wherein the composition is in the form of an emulsion.

11. A method according to claim 1 wherein the composition is in the form of an emulsifiable concentrate.

12. A method according to claim 1 wherein the composition is in the form of a wettable powder. 

1. A METHOD FOR STIMULATING PARTHENOCARPY IN FRUIT BEARING PLANTS WHICH COMPRISES APPLYING TO SAID PLANTS AT THE STAGE OF FLOWERING A PARTHENOCARPY STIMULATING AMOUNT OF A COMPOSITION COMPRISING AS AN ACTIVE INGREDIENT A COMPOUND SELECTED FROM THE GROUP CONSISTING OF:
 2. A method according to claim 1, wherein the halogen or halogeno moiety is selected from the group consisting of chlorine, bromine, iodine and fluorine.
 3. A method according to claim 1, wherein the active ingredient is 3-phenyl-4,9-dihydronaphtho(2,3-d)isoxazole-4,9-dione.
 4. A method according to claim 1, wherein the active ingredient is 3-(3-chloro-4-dimethylaminophenyl)-4,9-dihydronaphtho(2,3-d)isoxazole-4,9 -dione.
 5. A method according to claim 1, wherein the active ingredient is 3-phenyl-4,5-dihydronaphtho(2,1-d)isoxazole-4,5-dione.
 6. A method according to claim 1, wherein the active ingredient is 3-(4-methoxyphenyl)-4,9-dihydronaphtho(2,3-d)isoxazole-4,9-dione.
 7. A method according to claim 1, wherein the active ingredient is 3-(4-chlorophenyl)-4,9-dihydronaphtho(2,3-d)isoxazole-4,9-dione.
 8. A method according to claim 1, wherein the active ingredient is 3-methyl-4,5-dihydronaphtho(2,1-d)isoxazole-4,5-dione.
 9. A method according to claim 1 wherein the composition is in the form of a solution.
 10. A method according to claim 1 wherein the composition is in the form of an emulsion.
 11. A method according to claim 1 wherein the composition is in the form of an emulsifiable concentrate.
 12. A method according to claim 1 wherein the composition is in the form of a wettable powder. 